The Infrared Space Observatory (ISO)

The Infrared Space Observatory (ISO) was the world's first true orbiting
infrared observatory. Equipped with four highly-sophisticated and versatile
scientific instruments, it was launched by Ariane in November 1995 and
provided astronomers world-wide with a facility of unprecedented
sensitivity and capabilities for a detailed exploration of the Universe at
infrared wavelengths.

The two spectrometers (SWS and LWS), a camera
(ISOCAM) and an imaging photo-polarimeter (ISOPHOT) jointly covered
wavelengths from 2.5 to around 240 microns with spatial resolutions ranging
from 1.5 arcseconds (at the shortest wavelengths) to 90 arcseconds (at the
longer wavelengths). Its 60 cm diameter telescope was cooled by superfluid
liquid helium to temperatures of 2-4 K.

The mission was a great technical,
operational and scientific success with most satellite sub-systems
operating far better than specifications and with its scientific results
impacting practically all fields of astronomy. During its routine
operational phase, which lasted until April 1998 - almost a year longer
than specified, ISO successfully made some 30,000 individual imaging,
photometric, spectroscopic and polarimetric observations ranging from
objects in our own solar system right out to the most distant extragalactic
sources.

In the ensuing Post Operational Phases, which ended in 2006, the ISO archive
has been improved and enhanced both in functionality and in contents,
in order to maximise its long-term value and usability, as a legacy to
future generations of astronomers.